Update: Through a painstaking update to the Espoo internals, this problem has been essentially eliminated. Ignore the comments below.

When you’re holding button 6 (or RB), Pokey should release automatically when the parabola passes through the cross hair. The problem is the at it is not perfectly precise. This is due to details on how a digital computer simulates physical systems.

However it possible to account for the imprecision. You may notice that the auto release always releases the projectile just a little bit late. If you account for this lateness in your aim, then you might be more successful.

Are you having difficulty deriving mathematical expressions for the coefficients to the parabola? These two videos may help.

First, we’ll start with the case where the balloon provides buoyancy which exactly cancels the weight of the projectile. In doing so, I hope you see how to solve it with and without buoyancy.

After determining the “parabola” for the case when B=1 as described in the video above, I hope that you are now ready for the general case of a parabola with or without buoyancy.

If you still have some lingering confusion, you can consult the following video (coming soon).

Return to Espoo Help.

When you reach the end of the line… not the dead end, but the real end, you have one more thing you’re going to need to accomplish. You will need to fit your spuCraft into the small purple box, and keep it there, without touching any of the walls. To do this, you will need to lose almost all your energy. You do not need a trigger. You can lose energy manually.

When you first latch onto the swingling, a billboard states: “Find the end of the line… but which end?” The fact that you got to the dead end means that you are at the wrong end of the line and that you have to go to the other end.

So how are you going to get to the other end, when the conveyor belts are moving the wrong way?

Well… Here’s my advice to you. Do you see the orange and blue striped square? If you swing your third mass directly past the square, then the countdown ticks down. When the countdown reaches zero, something special happens.

I purposely hid that information from you. And if you look at the value of y when the spuCraft is near the bridge, you’ll see that I really went out of my way to hide that information from you.

I don’t want you to use the bridge height… so you can’t. And you don’t need it.

Think about the Lift challenge. In Lift, Pokey starts from rest then falls because of gravity. Then, a short time into the fall, it gets a net constant upward force, which slows down the descent and eventually turns the spuCraft around. To solve that problem, you did not need to know the initial height of Pokey. You could use the height and velocity of the spuCraft at some point along the way. Right?

If you think about it, the trajectory of the spuCraft in FreeFall is very similar. Just like lift, I’m not giving you the initial height of the spuCraft. I am giving you the (current) height and velocity of the spuCraft at all points along its trajectory, after it has moved a certain distance from the bridge.

Nope. All you need to know that it is always possible (barely) to land.

Instead of thinking about how to get past a portion of the domain before the gate does, I suggest that you ignore the gate and just think about how to get to the bottom (safely) as soon as possible. If you get to the bottom in as little time as possible, you are guaranteed to get past the gate.

Getting past the gate and not crashing on the landing pad is the hard part. The rest is easy.

You do NOT have to write scripts that automatically land the spuCraft. It is so much simpler to define a switch that will return to manual control. Then you can land by hand.

The way I solve the problem is to use the positions and velocities at the two points to calculate Fb. After that, the solution is identical to Novice.

Return to Lift Help.

Wily is very similar to Rookie, but the differences are important.

In the Intermediate level, you no longer have access to the buoyancy force, Fb. But in instead, you get position and velocity from another point on its path.

Can you think about how you can use this information to replace the old information you lost? Think about it!

If you’re still stuck, you can click here.

Return to Lift Help.

The latching condition is quite sensitive. Although it may appear that the payload is in the right place at the right time, it needs to be almost exact for the latch to occur.

The thing to note here is that when you tell the platform to go to a specific height, it doesn’t get there instantaneously. It takes a little time. Also, it takes a little time to come to a complete stop. To ensure that you have plenty of time to get the platform to the right place and bring it to a complete stop, I suggest the following things to avoid:

• Do not turn on your input script before the spuCraft passes the light gate. If you turn on your input script before the gate, then platform placement is based on bad information. Then, when the spuCraft does  pass through the gate, the platform hast to travel a long distance to get to the right place. Under those circumstances, it doesn’t get there in time.
• Do not wait to long, after passing the light gate, to turn on your script. Again, the platform might not reach its destination and come to a complete stop in time.

Return to Lift Help.